Sodium chloride, calcium chloride, urea, and the like are widely used as a snow-melting agent or an antifreezing agent.
However, the snow-melting agent containing a chloride and the like has a problem of remarkably accelerating frost damage and deterioration of concrete by separating flaky materials from the surface. In addition, chloride ions permeate concrete, gradually spread into the core of the concrete and ultimately reach steel rods, and produce rust in the steel rods by the reaction with oxygen. Concrete finally produces cracks due to expansion.
On the other hand, protection of the earth environment has become a big issue in recent years. Although urea is free from the above-mentioned problems with chloride, urea has other problems such as reactions with metals, nutrient enrichment due to the nitrogen content, production of mold and moss, a bad odor after decomposition, and the like.
Therefore, notwithstanding the effect of melting snow and preventing freezing, conventional snow-melting agents are not necessarily satisfactory in respect of environmental protection, preventing deterioration of concrete, and the like.
Furthermore, since conventional snow-melting agents are generally available in the form of a powder, there has been a problem of handling during application.